Light is the elixir of light in photography. This not only applied to the light you need when shooting a picture, but in addition to the lighting conditions when viewing the results. Light is needed to illuminate and to transilluminate depending on whether the subject is reflective or transparent.
A light box is the appropriate tool to transilluminate a transparent original. It seems at a first glance that this must be the simplest of all light sources: Take a square box, put some lamps in it, cover it with diffusion - done.
Without doubt this is a light source, but most likely completely inappropriate for a photographic application.
Because there are stringest requirements for transmitted light sources. The most important one is evenness: every spot on the luminous surface should have the same brightness. This is equally important for viewing and inspecting slides as for the photographic reproduction of transparent originals. Selected materials for the lit surface, a well-balanced design of interior reflectors and light conduction techniques are used to meet these requirements.
If you have to inspect colour qualities of a transparency or if you want to capture a colour original, then it is important that the light box has the correct colour properties. The light's stability is also very important to be able to get the perfect shot possible. If your subject has issues in hot environments, you would have to take precautions to reduce the thermal load of the original, which means an effective cooling system has to be integrated. Battery operation can also be an option for when you need to be on the road and not near a wall socket.
The Kaiser light boxes have different features according to the potential requirements. Now you only have to choose the appropriate size and then you have your luminous surface.